If you were doing a MM Al/Hg, I would say 65 minutes is way too slow for that scale. There really isn't a set drip time... the point is to drip in your ketone at a rate slow enough that the reaction doesn't get out of hand, but fast enough so you aren't adding ketone when the Al is already done reacting. MM gives an addition time of around 40mins. and a drip rate of 1 drop per second. In Dr. Gonzo's photo essay of the MM procedure, the author explains that he adjusted his drip rate to match the rate of the reaction... i.e., sometimes one drop per second was too slow. This reaction is really important to yields, so I think anyone doing a MM amination should keep close watch on it and not just start it and walk away. There are a lot of variables for the rxn, and each amination will be unique, therefore requiring constant attention. good luck peace